Ex-Microsoft CEO Steve Ballmer may have thought Twitter was a good bet. But his appetite for investing isn’t quite what it once was.

In October, Ballmer bought a major stake in Twitter that made him a bigger stakeholder at the time than current Twitter CEO and founder Jack Dorsey. In announcing the investment, he tweeted “glad I bought 4% past few months” and also praised Dorsey for making the company leaner and more focused.

Asked Wednesday night about his Twitter stake, Ballmer said it has helped to teach him a lesson.

“I don’t want to be an investor,” he said sheepishly at the Fortune Brainstorm Tech dinner in San Francisco.

Ballmer, who is now the owner of the Los Angeles Clippers, admitted he’s actually lost money on Twitter—at least on paper. Its shares have fallen nearly 45% since his announcement.

Still, Ballmer reiterated his belief in Twitter twtr on Wednesday, telling Fortune’s assistant managing editor Adam Lashinsky: “I think it is a very good brand, but its cost structure and product can be improved. It’s better to invest in things that have a path to improvement.”

Ballmer still holds stock in Microsoft, although he’s no longer considered an “insider,” or someone who holds knowledge of a company’s internal affairs and must report every trade publicly. “I see no reason to sell the stock unless I give it away or if it’s going to tank,” he said. “I prefer to be a holder and I believe in that.”

 

Ballmer does have one bone to pick with Microsoft: He believes the company should reveal more financial details about its enterprise cloud business. It’s an amusing thought because, while CEO, he failed to provide that same information.

“We should be able to see what revenue and gross margin is for the cloud services, for the hardware, and for the software,” Ballmer argued on Wednesday.

As for whether Microsoft is swayed by the request, Ballmer said that the company believes it has “sufficient disclosures.”

Having said that, Ballmer acknowledged that he’s not exactly close to Microsoft co-founder Bill Gates. Since “retirement,” he said that he’s barely seen Gates.

“We’ve gone on our own paths and don’t see each other much,” Ballmer said. “But our wives spent time together today, and that’s a good thing.”